1. Field
Example embodiment relate to a wafer carrier information management system and/or method for collecting information about wafer carriers and reporting the information to a higher system in a semiconductor processing line.
2. Description of the Related Art
With the recent introduction of an automatic physical distribution management system to semiconductor processing, wafers are conveyed and loaded using an auto guided vehicle, a laser guided vehicle, an overhead hoist transport (OHT), etc.
Buffers are arranged at the side of a path through which a wafer transferring vehicle is moved to temporarily store wafer carriers while the wafer transferring vehicle transfers wafer carriers. If the position of a buffer and a wafer carrier loaded in the buffer can be recognized, the operation of the wafer transferring vehicle can be efficiently managed when the wafer transferring vehicle loads a new wafer carrier in a buffer or conveys a wafer carrier loaded in a buffer. Furthermore, information about wafer carriers loaded in buffers helps in management of semiconductor processing.
A conventional wafer carrier information management method collects information about a wafer carrier loaded in a buffer and manages the collected information by recognizing the wafer carrier information from a transmitting/receiving unit attached to the wafer carrier while a wafer transferring vehicle unloads/loads the wafer carrier from/to the buffer because a system for collecting and managing the wafer carrier information is not provided to the buffer. FIG. 1 illustrates a conventional wafer carrier information management system using an OHT 30 as a wafer transferring vehicle. The OHT 30 loads a wafer carrier 20 in a buffer 10 or unloads a wafer carrier loaded in the buffer 10 while moving along a rail 31. The OHT 30 reads information about the wafer carrier 20 loaded in the buffer 10 while loading/unloading the wafer carrier 20 in/from the buffer 10 and transmits the read information to an OHT controller 32 that is a higher system of the OHT 30. The OHT controller 32 transmits the wafer carrier information to a wafer manager 40 of a semiconductor processing line such that the wafer manager 40 collects the information about the wafer carrier 20 in the buffer 10 and stores the information in a database.
As described above, when the wafer manager 40 of the semiconductor processing line manages wafer carrier information in the database, if the database has an error since system power is cut off or the system has trouble, an operator manually inputs data in order to recover the database or eliminate the wafer carrier from the buffer.
Furthermore, when the wafer carrier information is managed through the aforementioned method, it is difficult to acquire information about a wafer carrier loaded in a specific buffer in the semiconductor processing line. This makes wafer carrier management difficult.